Figure 13: Dot1Ag Loopback Test; Throughput Measurement - Alcatel-Lucent 7705 Service Manual

7705 SAR
BTS
Ports
A B
Legend:
Ethernet (virtual) private line
Ethernet PW
Physical link
Loopback
Linktrace (LT)
The linktrace function is supported by 802.1ag and Y.1731 on the 7705 SAR. A Linktrace
Message (LTM) is originated by a MEP and targeted to a peer MEP in the same MA and
within the same MD level. Its function is similar to IP traceroute. The peer MEP responds
with a Linktrace Reply (LTR) message after successful inspection of the LTM.

Throughput Measurement

Throughput measurement is performed by sending frames to the far end at an increasing rate
(up to wire speed) and measuring the percentage of frames received back. In general, the rate
is dependent on frame size; the larger the frame size, the lower the rate.
The Y.1731 specification recommends the use of unicast ETH-LB and ETH-Test frames to
measure throughput.
In Release 3.0 of the 7705 SAR, LBM processing and LBR generation are enhanced and
occur on the datapath, allowing the 7705 SAR to respond to loopback messages at wire
speed and making in-service throughput tests possible. Thus, if the 7705 SAR receives
LBMs at up to wire speed, it can generate up to an equal number of LBRs.
7705 SAR OS Services Guide

Figure 13: Dot1ag Loopback Test

Metro Ethernet
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